Non-volatile data storage devices, such as embedded memory devices and removable memory devices, have enabled increased portability of data and software applications. For example, multi-level cell (MLC) storage elements of a flash memory device may each store multiple bits of data, enhancing data storage density as compared to single-level cell (SLC) flash memory devices. As a result, flash memory devices may enable users to store and access a large amount of data.
Data stored at a flash memory data storage device may become less reliable over time. For example, a threshold voltage stored at a flash memory storage element may “shift” or lose charge over time due to charge leakage. The flash memory data storage device may track the length of time data has been stored at the flash memory storage element and may access the data in a manner determined by the length of time the data has been stored at the flash memory storage element. For example, if threshold voltages stored at the data storage device shift after a certain length of time, the data storage device may compensate for the shifting when accessing the data by adjusting one or more read thresholds used to sense the data.